Zinzani Sofia, Baletto Francesca
Università degli Studi di Milano - Dipartimento di Fisica, Via Celoria 16, Milano I-20133, Italy.
Phys Chem Chem Phys. 2024 Aug 22;26(33):21965-21973. doi: 10.1039/d4cp00916a.
The optimal design of nanoparticles and nanoalloys arises from the control of their morphology which depends on the synthesis process they undergo. Coalescence is widely accepted as one of the most common synthetic mechanisms, and it occurs both in the liquid and gas phases. Coalescence is when two existing seeds collide and aggregate into a larger object. The resulting aggregate is expected to be far from the equilibrium isomer, the global minimum of the potential energy surface. While the coalescence of nanoparticles is well studied in a vacuum, sparse computational studies are available for the coalescence in an environment. Using molecular dynamics simulations, we study the coalescence of Au and Pd nanoseeds surrounded by an interacting environment. Comparing the initial stages of the coalescence in a vacuum and the presence of an interacting environment, we show that the formation kinetics strongly depends on the environment and on the size of the nanoalloy. Furthermore, we show that it is possible to tune the resulting nanoalloys' surface chemical composition by changing their surrounding environment.
纳米颗粒和纳米合金的优化设计源于对其形态的控制，而形态取决于它们所经历的合成过程。聚结被广泛认为是最常见的合成机制之一，它在液相和气相中都会发生。聚结是指两个现有的晶种碰撞并聚合成一个更大的物体。预计所形成的聚集体远非平衡异构体，即势能面的全局最小值。虽然纳米颗粒在真空中的聚结已得到充分研究，但关于在环境中的聚结的计算研究却很少。我们使用分子动力学模拟研究了被相互作用环境包围的金和钯纳米晶种的聚结。通过比较在真空中和存在相互作用环境时聚结的初始阶段，我们表明形成动力学强烈依赖于环境和纳米合金的尺寸。此外，我们表明通过改变其周围环境可以调整所得纳米合金的表面化学成分。
